FREQUENCY OF VITAMIN B 12 DEFICIENCY IN PATIENTS WITH HYPOTHYROIDISM

Abstract

Background: Vitamin B12 deficiency is a frequently overlooked comorbidity in patients with hypothyroidism. Shared autoimmune pathways, impaired gastrointestinal absorption, and overlapping clinical features contribute to diagnostic difficulty. In low and middle income countries such as Pakistan, nutritional inadequacy further increases susceptibility, highlighting the need for locally generated epidemiological evidence. Objective: To determine the frequency of vitamin B12 deficiency among patients diagnosed with hypothyroidism attending a tertiary care hospital in Pakistan. Study Design: Cross sectional study. Settings: Outpatient Department of General Medicine, Nishtar Hospital, Multan. Duration of Study: January 2025 to June 2025. Methods: A total of 93 adult patients aged 20 to 60 years with biochemically confirmed hypothyroidism were enrolled using non probability consecutive sampling. Patients already receiving vitamin B12 supplementation were excluded. Serum vitamin B12 levels were measured using standard laboratory techniques, and deficiency was defined as a level below 200 pg/ml. Demographic characteristics, clinical features, and comorbid conditions were documented using a structured proforma. Data were analyzed using SPSS version 20. Quantitative variables were expressed as mean and standard deviation, while categorical variables were reported as frequencies and percentages. Results: The mean age of participants was 36.53 ± 10.40 years, with female predominance accounting for 72.0% of cases. The mean serum vitamin B12 level was 215.53 ± 151.29 pg/ml. Vitamin B12 deficiency was identified in 41 patients, corresponding to a frequency of 44.1%. Most participants were younger than 40 years (59.1%), belonged to urban areas (67.7%), and had a disease duration of one year or less (76.3%). Hypertension (29.0%) and diabetes mellitus (20.4%) were the most commonly observed comorbidities. Conclusion: Vitamin B12 deficiency is highly prevalent among patients with hypothyroidism in this tertiary care population. Incorporation of routine vitamin B12 screening into the standard evaluation of hypothyroid patients may enable early diagnosis and prevent avoidable hematological and neurological complications.